This application relates to occupant restraint systems and more particularly to restraint systems for use in over-the-highway vehicles equipped with sleeping bunks.
Vehicles such as highway tractors commonly contain a sleeping compartment or berth containing one or more beds for use by non-driving occupants. U.S. regulations, for example, require each vehicle of this type to have a restraint system for each bed or sleeping area that is used when the vehicle is moving and a non-driving occupant is using the bed. Frequently used restraint systems include flexible harnesses or netting that restrict the space in which an occupant lies or can catch the occupant during an emergency.
In a typical arrangement, one end of the harness or netting is attached to the vehicle, the harness or netting is draped over the bunk, and the other end is releasably attached to the vehicle. This provides an enclosure over the bunk. The releasable attachment may be such as a seat-belt buckle having a buckle and tongue, of the type used by the automotive industry in passenger cars. One disadvantage of these types of prior art restraint systems is the lack of padding attached to the restraint system to prevent or minimize injury from a collision. Their primary purpose is to prevent the occupant from falling off the bunk during normal use, such as when the occupant is sleeping in the vehicle.
U.S. Pat. No. 5,690,355 and No. 5,876,059 describe a restraint system that includes sections that can be folded out from the rear wall of the cab of a vehicle and extended up from the bunk's front edge, which is to say, the forward-most end of the bunk in the normal direction of travel of the vehicle. The sections may be padded and provided with airbags, and a vertical section can be automatically extended by a spring when the bunk is prepared for use.
U.S. Pat. No. 5,375,879 describes a collapsible occupant restraint system, in which a net is fixedly mounted to a web framework that is slidably mounted to a plurality of webs extendable and retractable by retracting devices. The net and webbing is extendable from a stored collapsed position to an in-use position over a bed having buckles that lockingly engage a plurality of tongues mounted to the framework.
Restraint systems of the type described are generally bulky whereas sleeping compartments are usually small spaces. Efficient use of the space is desired. When not in use, the restraint systems are typically stored above the bunk bed. Storage above the bunk protrudes into the small space, making the sleeping compartment more confined. It would be desirable to store the restraint system in a manner that would not impact living space. It would be further desirable to provide a restraint system having a mechanism, such as a seatbelt-style retractor, for quick and easy storage when the restraint system is not in use.
Other types of restraint systems employ airbags which are installed in a horizontal and/or vertical deployment position with respect to the prone occupant in the bed or sleeping area. The airbags deploy when there is an impact or event sufficient to trigger the airbag mechanism. Airbag deployment most likely will not occur during emergency stops or other non-impact situations that could impart significant forward momentum or inertia to an occupant using the bed. Moreover, airbags are relatively complex systems and expensive to install compared to harness or netting restraint systems. Once an airbag has been deployed, maintenance is required to install a new airbag. Installation of the airbags usually requires the vehicle to be out of service until the maintenance is completed. Optionally, an air cushion is installed. The air cushion does not enclose a recumbent occupant but rather is positioned vertically with respect to the recumbent occupant.
U.S. Pat. No. 6,367,839 to Langhoff describes a restraint system that includes at least two flexible straps having one end attached to a selected one of the vehicle or the bunk, and a second end. At least one energy absorbent pad is attached to the straps in a position relative to the bunk for providing restraint and secondary collision protection. When not in use, the restraint system is conveniently stored so as to provide minimal impact on cab space.
Such prior restraint systems can be improved in various aspects.